Classification of VWD by screening assays
| Type | VWF:Activity 50-166 (IU/dL)* | VWF:Antigen 50-249 (IU/dL)* | FVIII 50-186 (IU/dL)* | Activity:Antigen ratio | VWF Multimers |
|---|---|---|---|---|---|
| Type 1 | <50 | <50 | NL or D | ~1 | Uniformly D |
| Type 2 | |||||
| A | D | NL or D | NL or D | <0.5-0.7 | Lg and Int D |
| B | D | NL or D | NL or D | <0.5-0.7 | Lg D |
| M | D | NL or D | NL or D | <0.5-0.7 | NL |
| N | NL | NL | NL | ~1 | NL |
| Type 3 | <3 | <3 | <10 | -- | UD |
NL, normal; D, decreased; Lg, large; Int, intermediate; UD, undetected
Reference ranges adapted from Rodak's Hematology: Clinical Principles and Applications, 5th ed. Elsevier, St. Louis, MO.